Flowrate control device, in particular for medical use

ABSTRACT

The invention concerns a device comprising two components connected to each other with possible displacement of one component relative to the other, sealing means arranged between said two components, and flow rate adjusting means actuated by displacement of one component relative to the other. The invention is characterized in that the device comprises positioning means for placing the two components in two different positions, namely a first so-called sterilizing position, wherein said two components do not, or hardly exert, any stresses on the sealing means, and second so-called operating position, wherein said two components stress the sealing means to provide the required sealing conditions.

[0001] The present invention relates to a flowrate control device, inparticular for medical use.

[0002] Such a device is presently used in particular in infusion systemsfor controlling the flowrate of the infused liquid.

[0003] Flowrate control is to be understood in the broad sense of theterm and also concerns flow distributors with one or more valves andwith opening and closure functions.

[0004] A known device comprises two components connected to one anotherpivotably, one of which delimits a conduit intended to be connected to asource of fluid, in particular a bag of liquid for infusion, and ofwhich the other delimits a conduit intended to be connected to a tubefor delivery of the liquid.

[0005] In one configuration, one of said components comprises a base inwhich there is formed, coaxially with respect to the axis of pivoting ofone component relative to the other, a circular groove extending alongslightly less than one turn and having a variable depth along itslength; the conduit formed in this component opens into this groove. Theother component is integral in rotation with a sealing washer made ofresilient material, having an orifice communicating on the one hand withthe conduit of this other component and on the other hand with saidcircular groove.

[0006] The pivoting of this other component relative to the firstcomponent mentioned permits displacement of the orifice of the sealingwasher along the groove and, consequently, on account of the differentdepth of this groove at different locations thereof, permits variationof the cross section of the fluid delivery conduit depending on theangular position of one component relative to the other.

[0007] When the required sealing is obtained, the washer is clampedtight between the two components of the device, with the result thatquite substantial stresses are generated on this washer.

[0008] These stresses prohibit steam sterilization of the device. Thereason is that the increase in temperature would lead to a softening ofthe material constituting said components and, also, said washer, and,in view of the aforementioned stresses, there would be a risk of thesematerials exhibiting creep, which would adversely affect theleaktightness and functioning of the device, or could even riskrendering the device inoperative.

[0009] For this reason, a device of this type is presently sterilizedeither by particle radiation or by means of a gas permittinglow-temperature sterilization, for example ethylene oxide.

[0010] The main disadvantage of these methods of sterilization is thatthey necessitate strict safety measures and are therefore relativelycomplex to perform. The use of a low-temperature sterilization gas alsohas the disadvantage of disseminating chemical products into theenvironment.

[0011] According to another design, the sealing of the device isobtained by two conical components which bear against one another withpressure. In this case too, sterilization poses a problem because theplastic components have a tendency to exhibit creep under stress, whichsubsequently results in defective sealing.

[0012] The invention aims to overcome these disadvantages by makingavailable a control device which can be sterilized by steam.

[0013] It is also an object of the invention to make available a controldevice which provides perfect sealing and has an optimized structurefrom the point of view of its manufacture.

[0014] The device according to the invention comprises, in a mannerknown per se, two components connected to one another with possibilityof displacement of one component relative to the other, sealing meansplaced between these two components, and flowrate control means actuatedby the displacement of one component relative to the other.

[0015] According to the invention, the device comprises positioningmeans allowing the two components to be placed in two differentpositions, namely a first position, called the “sterilizing” position,in which these two components do not exert, or hardly exert, anystresses on the sealing means, and a second position, called the“operating” position, in which these two components stress the sealingmeans in such a way as to obtain the required sealing.

[0016] The two components of the device are placed in the “sterilizing”position at the time of sterilization of the device, in order to cancelall the stresses to which these components are subjected when they clampthe sealing member in order to obtain the required sealing. It thenbecomes possible to sterilize this device with steam, without theheating which results from this type of sterilization causing any riskof creep of the material from which these components and the sealingmember are made. Such sterilization is thus made possible withoutadversely affecting the sealing and functioning of the device.

[0017] Preferably, said positioning means comprise:

[0018] at least one groove formed in one of said components;

[0019] at least one boss integral with the other component and slidingin this groove in order to permit displacement of the componentsrelative to one another; and

[0020] at least one clearance communicating with the groove, in whichclearance the boss can be engaged in order to permit displacement of thecomponent comprising the groove relative to the component comprising theboss, from said operating position to said sterilizing position, andvice versa.

[0021] This displacement is thus made possible in a way which is simpleto manufacture and practical to use.

[0022] Advantageously, each groove and/or each boss has inclined zonesforming ramps, these ramps facilitating the movement of the componentsfrom the sterilizing position to the operating position counter to theelastic restoring force of the sealing means.

[0023] According to a preferred embodiment of the invention, when thedevice comprises at least one groove and at least one boss as mentionedabove, the groove has at least one entry in which a boss can be engagedin a defined position of one component relative to the other, and one ofthe components comprises at least one immobilizing catch, while theother component comprises at least one corresponding immobilizing catch,these catches being configured in such a way that the catch or catchesof one component can snap in beyond the catch or catches of the othercomponent during the first displacement of one component relative to theother and can then be immobilized beyond these in such a way as toprevent any return of the components to the position in which each bossis situated opposite each entry.

[0024] The device can thus be assembled in a way which is particularlysimple and easy to perform.

[0025] According to one embodiment, the sealing means placed between thetwo components (2, 3) are formed by a separate sealing member (4).

[0026] Preferably, the sealing member has a sealing portion with aU-shaped cross section, and said components have shapes which are suchthat, when they are joined together, they enclose this sealing portionfrom all directions.

[0027] Perfect sealing is thus obtained.

[0028] According to a preferred embodiment of the invention, saidcomponents are connected pivotably to one another, and one of thecomponents delimits a conduit intended to be connected to a source offluid, while the other component delimits a conduit intended to beconnected to a tube for delivery of said fluid; one of said componentscomprises a wall in which there is formed, coaxially with respect to theaxis of pivoting of one component relative to the other, a circulargroove which extends along lightly less than one turn and has a variabledepth along its length, and the conduit formed in this component opensinto this groove; the other component is integral in rotation with thesealing member which has an orifice communicating on the one hand withthe conduit of this other component and on the other hand with saidcircular groove; the pivoting of this other component relative to thefirst component mentioned permits displacement of the orifice of thesealing member along the groove and, consequently, on account of thedifferent depth of this groove at different locations thereof, permitsvariation of the cross section of the fluid delivery conduit dependingon the angular position of one component relative to the other.

[0029] One of the components of the device can comprise at least oneslot opening to the outside, and the other component of the device canbe integral in rotation with a ring which comprises data relating to theflowrate controlled by means of the device, said data coming into linewith said slot in the different angular positions of the componentintegral with the ring relative to the component comprising the slot.

[0030] According to one embodiment, the sealing means are formed by twocomplementary conical surfaces which bear against one another and belongrespectively to the components (2, 3).

[0031] To ensure that it is clearly understood, the invention is againdescribed below with reference to the attached diagrammatic drawingwhich shows, as non-limiting examples, two embodiments of the deviceaccording to the invention.

[0032]FIG. 1 is a perspective view of the components of a flowratecontrol device, before assembly;

[0033]FIG. 2 is a perspective view of these components at another angle;

[0034]FIG. 3 is a perspective view, on an enlarged scale, of one of itscomponents, with part cut away;

[0035]FIG. 4 is a perspective view of another of its components, againon an enlarged scale;

[0036]FIG. 5 is a view of the components, in a cross section passingthrough the axis of these components, before assembly, and

[0037]FIG. 6 is a similar view to FIG. 5, on an enlarged scale, afterassembly of said components,

[0038]FIGS. 7 and 8 show a three-way valve in transverse section andlongitudinal section, respectively.

[0039] FIGS. 1 to 6 show a flowrate control device 1 for medical use.

[0040] This device 1 comprises a first component 2, a second component 3intended to be connected pivotably to the component 2, a sealing member4, and a ring 5.

[0041] The component 2 comprises an outer peripheral wall 10, an innerperipheral wall 11, a hollow central stub 12, a base 13, two slots 14formed in the wall 10, three bosses 15 projecting radially inward fromthe inner face of the wall 11, and an immobilizing catch 16 alsoprojecting radially inward from this same internal face.

[0042] The wall 10 has anti-slip contours on its outer face.

[0043] As the figures show, the wall 11 is formed at a distance from thewall 10, so that these walls 10, 11 delimit between them an annularspace in which the ring 5 can be engaged and can pivot.

[0044] The stub 12 is arranged coaxially with respect to the component2. It is evident more particularly from FIG. 3 that it has an axial hole20 communicating, via a circular groove 21 and a longitudinal groove 22,with a circular groove 23 formed in the base 13, coaxially with respectto the stub 12. It is evident from FIG. 3 that this groove 23 extendsalong slightly less than one turn and that it has a variable depth alongits length.

[0045] The hole 20 communicates with the space delimited internally bythe stub 12, which itself opens to the outside of the component 2.

[0046]FIG. 5 shows that the base 13 forms a circular recess 24 aroundthe stub 12.

[0047] The bosses 15 are arranged at 120 degrees to one another and aresituated at three different heights of the wall 11. They have indentedzones at their edges directed toward the base 13 and in the area of oneof their ends, these zones thus forming inclined walls 15 a.

[0048] The catch 16 is formed near the stub 15 situated highest, at theside thereof remote from the end having the wall 15 a. This catch 16 isconfigured to permit snap-fitting, that is to say has an inclined wall16 a and a wall 16 b oriented radially.

[0049] The component 3 comprises a peripheral wall 30, a base 31, and ahollow central stub 32.

[0050] The wall 30 has a flange 33 protruding from its outer face,substantially at half the height of the latter, this flange 33 beingintended to bear against the upper edge of the wall 10 when thecomponents 2 and 3 are joined to one another.

[0051] This flange 33 delimits an “outer” part of the wall 30, that isto say situated outside the device 1 after assembly of the latter, andan “inner” part of this wall 30, that is to say intended to be engagedin the component 2.

[0052] The outer part has anti-slip contours on its outer face.

[0053] The inner part comprises ribs 35 a, 35 b, 35 c, 35 d whichproject radially outward and between them define three superposedchannels. The rib 35 a nearest the base 31 is interrupted over anangular distance greater than the angular length of a boss 15, thusdelimiting a zone 36 a of entry of one of these bosses 15 into thechannel nearest the base 31. The rib 35 b is interrupted in the same wayover an angular distance greater than the angular length of a boss 15,but at a location offset by 120 degrees relative to the zone of entry 36a, thereby delimiting a zone of entry 36 b of one of the bosses 15 intothe intermediate channel. In the same way, the rib 35 c is interruptedover an angular length greater than the angular distance of a boss 15,but at a location offset by 120 degrees relative to the zone of entry 36b, thereby delimiting a zone 36 c of entry of one of the bosses 15 intothe channel farthest from the base 31.

[0054] The wall 30 additionally comprises a snap-fit catch 37 and apositioning limit stop 38, being an upward continuation of the adjacentend of the rib 35 c. The inclined wall 37 a of the catch 37 is directedtoward the limit stop 38.

[0055] Below the flange 33, the component 3 comprises a stud 39projecting radially outward.

[0056] The base 31 comprises a ring of radial crenelations 40 projectingaxially from its outer face.

[0057] In addition, as is shown more particularly in FIG. 4, the base 31has a hole 41 passing through it, connected, via a longitudinal groove42 and a circular groove 43, to an orifice 44 formed in a shoulder ofthe stub 32. The distance of the hole 41 from the axis of revolution ofthe component 3 corresponds to the radius of the circular groove 23, sothat this hole 41 is situated opposite this groove 23 and can travel thelatter when the component 3 is pivoted with respect to the component 2.

[0058] The stub 32 is formed coaxially with respect to the component 3.Beyond the wall forming the aforementioned shoulder, it has a connectionnozzle 45, for example of the Luer type, projecting opposite the base31.

[0059] The sealing member 4 is made of a resilient material such as asilicone. It has a hollow central stub 50, a base 51, and a raisedperipheral edge 52.

[0060] The stub 50 is dimensioned externally to engage tightly in thelower part of the stub 32 and is dimensioned internally to be engaged onthe stub 12 with the possibility of pivoting relative to the latter.

[0061] The base 51 has radial crenelations 55 able to engage tightly inthe spaces delimited by the crenelations 40, and vice versa, so as toensure a rotational connection between this member 4 and the component3. The dimensions of this base 51, and those of the peripheral edge 52,are such that this base 51 and this edge 52 can be engaged tightly inthe circular recess 24, but with the possibility of pivoting relative tothe component 2.

[0062] This base 51 comprises a hole 56 which comes into line with thehole 41 when the member 4 is joined to the component 3.

[0063] The ring 5 has a rim 60 projecting radially inward, and a notch61 formed in this rim 60. This rim 60 permits engagement of the ring 5on the wall 30 until engagement of the stud 39 in the notch 61, whichensures rotational wedging of this ring 5 in relation to the component3.

[0064] The ring 5 additionally comprises a series of data items 62relating to the flowrate which can be controlled by the device 1, saiddata being printed on its outer face, and which data comes into linewith the slots 14 in the different angular positions of the component 3relative to the component 2. These data 62 thus inform the user of thecontrolled flowrate.

[0065] The device 1 is assembled by engaging the member 4 on thecomponent 3, engaging the ring 5 in the circular space delimited by thewalls 10 and 11, then engaging the assembly of component 3/member 4 inthe component 2, with the bosses 15 situated opposite zones 36 a to 36c. In the area of the zone 36 c, the limit stop 38 directs the catch 16into the space delimited between this limit stop 38 and the inclinedwall 37 a of the catch 37. When the component 3 is pivoted with respectto the component 2 in the clockwise direction in the example representedin the figures, the inclined walls 16 a and 37 a of the catches 16 and37 slide on one another, which, by elastic deformation of the component3, causes the catch 16 to pass beyond the catch 37 and be locked behindit. The assembly of components 3 and 2 has thus been made irreversible.

[0066] In this state of assembly, the orifice 20, the grooves 21, 22 and23, the holes 56 and 41, the grooves 42 and 43, and the orifice 44delimit a conduit passing right through the device 1. The base of thecomponent 2 can be connected to a source of liquid for infusion, forexample a flexible bag, and the nozzle 45 can be connected to a tube fordelivering the liquid to a patient.

[0067] The pivoting of the component 3 relative to the component 2 makesit possible to displace the hole 56 along the groove 23 and thus tovary, according to the angular position of this hole 56 relative to thisgroove 23, the cross section of said conduit passing through the device1, and thus vary the flowrate obtained.

[0068] The ribs 35 a to 35 d and the bosses 15 are formed in such a waythat, when the bosses 15 are engaged in the channels delimited by theseribs 35 a to 35 d, the components 2 and 3 clamp the member 4 betweenthem. These ribs 35 a to 35 d and these bosses 15 thus make it possibleto obtain the required sealing between these components 2 and 3.

[0069] When the bosses 15 are situated in the zones 36 a to 36 c, thecomponent 3 can move axially with respect to the component 2, betweenthe operating position of the device 1, in which the components 2 and 3clamp the member 4 between them, and a sterilizing position, in whichthe stress exerted on this member 4 by the components 2 and 3 isrelaxed.

[0070] The inclined walls 15 a of the bosses 15 makes it possible toeasily re-engage the bosses 15 in the channels delimited by the ribs 35a to 35 d and to easily recompress the member 4 when one wishes tochange from the sterilizing position to the operating position.

[0071]FIGS. 7 and 8 show a three-way valve comprising a body 62 in whicha plug 63 is mounted. Three tubes (64, 65, 66) open out at the center ofthe body and are used to assemble three nozzles (not shown in thedrawing). The sealing between the body 62 and the plug 63 is obtained byconical surfaces 67, 68 belonging, respectively, to the body and to theplug, and bearing against one another. The structure allowing the plugto be changed from the sterilizing position to the operating position isthe same as before and is not described here.

[0072] As will be apparent from the foregoing, the invention brings adecisive improvement to the prior art by making available a flowratecontrol device for medical use which can be sterilized by means ofsteam, provides perfect sealing and has an optimized structure from thepoint of view of its manufacture.

[0073] It will be appreciated that the invention is not limited to theembodiments described above by way of example, and that instead itencompasses all alternative embodiments coming within the scope ofprotection defined by the attached claims.

1. A flowrate control device, in particular for medical use, comprisingtwo components connected to one another with possibility of displacementof one component relative to the other, sealing means placed betweenthese two components, and flowrate control means actuated by thedisplacement of one component relative to the other; said device beingcharacterized in that it comprises positioning means allowing the twocomponents to be placed in two different positions, namely a firstposition, called the “sterilizing” position, in which these twocomponents do not exert, or hardly exert, any stresses on the sealingmeans, and a second position, called the “operating” position, in whichthese two components stress the sealing means in such a way as to obtainthe required sealing.
 2. The device as claimed in claim 1, characterizedin that the positioning means comprise: at least one groove formed inone of said components; at least one boss integral with the othercomponent and sliding in this groove in order to permit displacement ofthe components relative to one another; and at least one clearancecommunicating with the groove, in which clearance the boss can beengaged in order to permit displacement of the component comprising thegroove relative to the component comprising the boss, from saidoperating position to said sterilizing position, and vice versa.
 3. Thedevice as claimed in claim 2, characterized in that each groove and/oreach boss has inclined zones forming ramps, these ramps facilitating themovement of the components from the sterilizing position to the positioncounter to the elastic restoring force of the sealing means.
 4. Thedevice as claimed in claim 2, characterized in that the groove has atleast one entry in which a boss can be engaged in a defined position ofone component relative to the other, and in that one of the componentscomprises at least one immobilizing catch, while the other componentcomprises at least one corresponding immobilizing catch, these catchesbeing configured in such a way that the catch or catches of onecomponent can snap in beyond the catch or catches of the other componentduring the first displacement of one component relative to the other andcan then be immobilized beyond these in such a way as to prevent anyreturn of the components to the position in which each boss is situatedopposite each entry.
 5. The device as claimed in claim 1, characterizedin that the sealing means placed between the two component are formed bya separate sealing member.
 6. The devices as claimed in claim 5,characterized in that the sealing member has a sealing portion with aU-shaped cross section, and in that said components have shapes whichare such that, when they are joined together, they enclose this sealingportion from all directions.
 7. The devices as claimed in claim 5,characterized in that said components are connected pivotably to oneanother, and in that one of the components delimits a conduit intendedto be connected to a source of fluid, while the other component delimitsa conduit intended to be connected to a tube for delivery of said fluid;one of said components comprises a wall in which there is formed,coaxially with respect to the axis of pivoting of one component relativeto the other, a circular groove which extends along slightly less thanone turn and has a variable depth along its length, and the conduitformed in this component opens into this grooves; the other component isintegral in rotation with the sealing member which has an orificecommunicating on the one hand with the conduit of this other componentand on the other hand with said circular groove; the pivoting of thisother component relative to the first component mentioned permitsdisplacement of the orifice of the sealing member along the groove and,consequently, on account of the different depth of this groove atdifferent locations thereof, permits variation of the cross section ofthe fluid delivery conduit depending on the angular position of onecomponent relative to the other.
 8. The device as claimed in claim 1,characterized in that one of said components comprises at least one slotopening to the outside, and in that the other of said components isintegral in rotation with a ring which comprises data relating to theflowrate controlled by means of the device, said data coming into linewith said slot in the different angular positions of the components,integral with the rings, relative to the component, comprising the slot.9. The device as claimed in claim 1, characterized in that the sealingmeans are formed by two complementary conical surfaces which bearagainst one another and belong respectively to the component.